This invention relates to an apparatus and method for lifting two axles onto the undersurface of an automotive vehicle chassis while the chassis is being moved and supported by an overhead conveyor. The invention is particularly applicable for use in a vehicle assembly process employing a moving assembly line.
In some prior art vehicle assembly systems, mechanical lift systems have been employed for lifting two axles onto the undersurfaces of a moving vehicle chassis, so that workers on a moving platform can fasten the axles to the chassis without having to exert any human lifting forces on the axles. Each axle typically weighs between two hundred and three hundred pounds, so that mechanical lift systems greatly simplify and facilitate the operation of connecting the axles to the moving vehicle chassis.
Prior art axle lift systems have been powered by electrical power mechanisms that received electrical power through an electrical cable running from a stationary power source along the factory floor to the movable worker-support platform. In another arrangement electrical power was supplied through a fixed rail on the factory floor. In such arrangements the electrical supply system poses a human safety problem, since there is a danger that humans or various fluids can, in some circumstances, come into contact with the electrical power supply components.